Add unit test for error case

staging/src/k8s.io/kubectl/pkg/cmd/rollout/rollout_restart_test.go

@@ -23,6 +23,8 @@ import (
 	"strings"
 	"testing"
 
+	"github.com/stretchr/testify/assert"
+
 	appsv1 "k8s.io/api/apps/v1"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/apimachinery/pkg/runtime/schema"
@@ -70,6 +72,56 @@ func TestRolloutRestartOne(t *testing.T) {
 	}
 }
 
+func TestRolloutRestartError(t *testing.T) {
+	deploymentName := "deployment/nginx-deployment"
+	ns := scheme.Codecs.WithoutConversion()
+	tf := cmdtesting.NewTestFactory().WithNamespace("test")
+
+	info, _ := runtime.SerializerInfoForMediaType(ns.SupportedMediaTypes(), runtime.ContentTypeJSON)
+	encoder := ns.EncoderForVersion(info.Serializer, rolloutRestartGroupVersionEncoder)
+	tf.Client = &RolloutRestartRESTClient{
+		RESTClient: &fake.RESTClient{
+			GroupVersion:         rolloutRestartGroupVersionEncoder,
+			NegotiatedSerializer: ns,
+			Client: fake.CreateHTTPClient(func(req *http.Request) (*http.Response, error) {
+				switch p, m := req.URL.Path, req.Method; {
+				case p == "/namespaces/test/deployments/nginx-deployment" && (m == "GET" || m == "PATCH"):
+					responseDeployment := &appsv1.Deployment{}
+					responseDeployment.Name = deploymentName
+					body := ioutil.NopCloser(bytes.NewReader([]byte(runtime.EncodeOrDie(encoder, responseDeployment))))
+					return &http.Response{StatusCode: http.StatusOK, Header: cmdtesting.DefaultHeader(), Body: body}, nil
+				default:
+					t.Fatalf("unexpected request: %#v\n%#v", req.URL, req)
+					return nil, nil
+				}
+			}),
+		},
+	}
+
+	streams, _, bufOut, _ := genericclioptions.NewTestIOStreams()
+	opt := NewRolloutRestartOptions(streams)
+	err := opt.Complete(tf, nil, []string{deploymentName})
+	assert.NoError(t, err)
+	err = opt.Validate()
+	assert.NoError(t, err)
+	opt.Restarter = func(obj runtime.Object) ([]byte, error) {
+		return runtime.Encode(scheme.Codecs.LegacyCodec(appsv1.SchemeGroupVersion), obj)
+	}
+
+	expectedErr := "failed to create patch for nginx-deployment: if restart has already been triggered within the past second, please wait before attempting to trigger another"
+	err = opt.RunRestart()
+	if err == nil {
+		t.Errorf("error expected but not fired")
+	}
+	if err.Error() != expectedErr {
+		t.Errorf("unexpected error fired %v", err)
+	}
+
+	if bufOut.String() != "" {
+		t.Errorf("unexpected message")
+	}
+}
+
 // Tests that giving selectors with no matching objects shows an error
 func TestRolloutRestartSelectorNone(t *testing.T) {
 	labelSelector := "app=test"